1. Field of the Invention
The present invention relates to crystal oscillator devices and electronic apparatuses including the crystal oscillator devices, and more specifically, to a crystal oscillator device suitable for use in a vehicle and an electronic apparatus including the crystal oscillator device.
2. Description of the Related Art
When an oscillator device including a crystal resonator is used in a vehicle-mounted apparatus, such as a global positioning system (GPS) used as a navigation system, the oscillation frequency occasionally changes instantaneously due to vibration of the vehicle. This is caused by strong vibration applied to a crystal blank included in the crystal resonator.
The crystal oscillator device is typically used in a cellular phone. Since the cellular phone is usually held in the hand of a user when it is being used, the crystal blank does not receive strong vibration even when the cellular phone is used in a vehicle since the hand of the user acts as a damper. However, since the use of the cellular phone while driving is dangerous, it is desirable to fix the cellular phone to the vehicle. In such a case, there is a risk that a problem similar to that of the GPS will occur.
Accordingly, configurations for preventing strong vibrations of the crystal oscillator device are disclosed in Japanese Unexamined Patent Application Publications Nos. 5-332399 and 2000-27942.
According to the configuration disclosed in the Japanese Unexamined Patent Application Publication No. 5-332399, the entire body of the crystal oscillator device is supported by coil springs arranged radially around the crystal oscillator device.
In addition, according to the configuration disclosed in the Japanese Unexamined Patent Application Publication No. 2000-27942, the entire body of the crystal oscillator device is supported by coil springs arranged only along a direction in which high vibration accelerations are applied.
The configurations according to the above-described publications have outstanding vibration isolation performance since the coil springs are used. However, since the size of the vibration isolation structure is relatively large even when the coil springs are arranged only along a single direction, it is difficult to reduce the size of the crystal oscillator device and save space. In addition, it is difficult to reduce costs of such a structure.